In the harvesting of fruit, and particularly citrus fruit such as oranges, automated harvesting equipment has made dramatic strides forward in the last few years. However, there have been some misgivings of previous devices due to a tendency to harm the fruit by tearing or bruising the skin. That is, in order to remove a piece of citrus fruit from the tree without ruining the fruit, it is a prerequisite that the fruit be grasped by the mechanical picker without penetrating the skin. If the skin is broken, or even bruised, especially in the area around the stem, the fruit rapidly deteriorates and spoils by the time it reaches the market.
One method of manually picking fruit from the tree is for the picker to simultaneously apply an outward pulling force and bending action to the stem of the fruit. Mechanical harvesting equipment used heretofore has tried to emulate this technique. While this prior equipment performs generally satisfactorily, some tearing and bruising of the fruit occurs during picking and conveying.
I have found that an improved picking operation is provided when, in addition to simultaneously pulling and bending the stem of the fruit, the fruit is also slightly twisted about the stem. When these three forces are simultaneously applied, I have found that the stem snaps more easily and cleanly from the surface of the fruit, thus minimizing the chances of the mechanical picker damaging the skin. The pulling, bending and twisting of the fruit must be performed firmly to effect the separation, yet gently to avoid bruising the skin.
Prior harvesting equipment, although capable of picking large quantities of fruit from a tree, insofar as I am aware, does not provide the simultaneous actions of pulling, bending and twisting which I have found to be desirable for cleanly separating the fruit from the stem. For example, in the U.S. Pat. to Swift, No. 3,552,107, there is shown one apparatus containing a plurality of fingers which are caused to bodily rotate on a housing. A portion of the fingers extends outside the housing during rotation for engaging the hanging fruit. The rigid, bodily rotating fingers produce pulling forces to the fruit to remove the fruit from the tree. There is substantially no simultaneous bending of the stem. It is clear no twisting action of the fruit during picking is contemplated. Thus some tearing of the fruit, particularly adjacent the stem, may be observed. In addition, the rigid fingers bumping into the fruit during rotation, rather than a gentle cradling action, can be responsible for bruising and occasionally even cutting into the skin.
Another difficulty found using prior art harvesting equipment is that branches of the tree tend to become entangled with the fruit picking mechanism. This entanglement ruins the limbs and the fruit bearing blossoms of the tree, interferes with the fruit picking process by creating down time, and occasionally even damages the fruit picking mechanism.